From nobody Fri Oct 17 10:31:35 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18E5CC433FE for ; Wed, 19 Oct 2022 10:57:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234311AbiJSK5W (ORCPT ); Wed, 19 Oct 2022 06:57:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234710AbiJSK43 (ORCPT ); Wed, 19 Oct 2022 06:56:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBCBD4BD03; Wed, 19 Oct 2022 03:27:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 16819B824A4; Wed, 19 Oct 2022 09:09:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80D5FC433D6; Wed, 19 Oct 2022 09:09:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666170547; bh=0yRnkpEfxS7tWFboF4T+L+HG5P/SvlF22wbvGiSDb4M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P33CsgQrc1pEfq2TT84O8Yet7B/OrLa3r2QhN/O1xB9cEPA596Ajw4n8x2A1OFUhF oH6rxeB1fk09M4mdO8vi8AUnJxf2MAeThamxsOUi/5JtcWqu0w7BLrWNwzSes1MZXk pVoSnROtb8yXKomKaWbu4r4xdP5r4I5OSb2EVaCs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Herbert Xu , syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com, Khalid Masum , Steffen Klassert , Sasha Levin Subject: [PATCH 6.0 696/862] xfrm: Update ipcomp_scratches with NULL when freed Date: Wed, 19 Oct 2022 10:33:03 +0200 Message-Id: <20221019083320.733613690@linuxfoundation.org> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221019083249.951566199@linuxfoundation.org> References: <20221019083249.951566199@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Khalid Masum [ Upstream commit 8a04d2fc700f717104bfb95b0f6694e448a4537f ] Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address. So when we try to free the percpu scratches using ipcomp_free_scratches() it tries to vfree non existent vm area. Described below: static void * __percpu *ipcomp_alloc_scratches(void) { ... scratches =3D alloc_percpu(void *); if (!scratches) return NULL; ipcomp_scratches does not know about this allocation failure. Therefore holding the old obsolete address. ... } So when we free, static void ipcomp_free_scratches(void) { ... scratches =3D ipcomp_scratches; Assigning obsolete address from ipcomp_scratches if (!scratches) return; for_each_possible_cpu(i) vfree(*per_cpu_ptr(scratches, i)); Trying to free non existent page, causing warning: trying to vfree existent vm area. ... } Fix this breakage by updating ipcomp_scrtches with NULL when scratches is freed Suggested-by: Herbert Xu Reported-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com Tested-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com Signed-off-by: Khalid Masum Acked-by: Herbert Xu Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/xfrm/xfrm_ipcomp.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c index cb40ff0ff28d..92ad336a83ab 100644 --- a/net/xfrm/xfrm_ipcomp.c +++ b/net/xfrm/xfrm_ipcomp.c @@ -203,6 +203,7 @@ static void ipcomp_free_scratches(void) vfree(*per_cpu_ptr(scratches, i)); =20 free_percpu(scratches); + ipcomp_scratches =3D NULL; } =20 static void * __percpu *ipcomp_alloc_scratches(void) --=20 2.35.1